Fabrication of Polyurethane/Polylactide (PU/PLDL) Nanofibers Using Electrospinning Method

Polylactide and aliphatic polyurethane are biodegradable synthetic polymers which are broadly used as biomaterials in regenerative medicine for implants and scaffolds for tissue engineering. In this paper, the detailed studies of the fabrication of the electrospun fibers of polyurethane/polylactide mixtures were described. The influence of the used solvent (dimethylformamide (DMF)) and diluents (acetone and dichloromethane (DCM)) on the rheological parameters and electrospinning of the described mixtures was examined. Rheological studies showed that polyure-thane/polylactide mixtures have mostly non-Newtonian character, strongly influenced by the diluent. Solutions containing 50 wt.% or more of polyurethane became less viscous after the addition of DCM or acetone, whereas those with bigger amount of polylactide showed higher viscosity after the addition of DCM and lower viscosity after the addition of acetone. Optimized electrospinning process has been elaborated. Fibers with diameters from 250 nm up to 1 mu m have been produced and compared. Pure acetone worsened the electrospinning process, but the more DCM was in the mixture, the thinner and more aligned fibers were produced.

Automated summary

This paper described the detailed studies of fabricating electrospun fibers of polyurethane/polylactide mixtures, with a focus on the influence of different solvents and diluents on the rheological parameters and electrospinning process. It was found that solutions with higher polyurethane content became less viscous with the addition of acetone or DCM, while solutions with more polylactide showed different viscosity changes. The optimized electrospinning process resulted in fibers with diameters ranging from 250 nm to 1 µm, with thinner and more aligned fibers produced when more DCM was present in the mixture.